Although in rare cases the vaccine may have side effects, the probability of those side effects is lower than the probability of Covid-19 infection and consequential infecting other individuals.
However, certain groups should not get vaccinated, at least for now. And for some of them, vaccination will not be permitted.
As there were no children participants in the very first clinical studies of Covid-19 vaccines, vaccination of children was therefore not allowed. Currently, there is a sufficient amount of relevant information for the approval of some of the children's cohorts. The European Commission approved the Comirnaty vaccine (by Pfizer/BioNTech) and Spikevax (by Moderna) based on EMA recommendation for children over 12 years.
Dated on the 25th of November 2021, EMA recommended the Comirnaty vaccine for children between 5 and 11 years. This recommendation has been adopted by European Commission, therefore children in the above-mentioned cohort can be vaccinated with a lower dose.
The Czech Vaccinological Society in its report recommends vaccination of children older than 5 years.
People with allergic diseases
During real vaccination by mRNA vaccine – not in clinical studies – anaphylactic reactions have been reported. The risk of anaphylactic reaction after mRNA vaccination is negligible – one in hundred/four hundred thousand doses. The probability is higher in comparison with routine vaccines but still very low. The majority of anaphylactic reactions come within 15 minutes after vaccination and are typical for individuals diagnosed with previous vaccine-related allergies or injection therapy allergies. These factors are not marked as a contraindication for a vaccination, but you should be careful in this case. mRNA vaccine may be used after informing the individual about the possible risk of severe allergic reaction and take this into account while weighing up risks and benefits of vaccination. Individuals with an immediate allergic reaction after the first dose of the vaccine should not be vaccinated with the second dose. Symptoms of hypersensitivity – anaphylaxis, urticaria, angioedema, respiratory distress (wheezing or stridor) – appearing within an hour of receiving the vaccine are considered to be an immediate allergic reaction.
mRNA vaccines are contraindicated for individuals having an immediate allergic reaction after any part of the vaccine. Both mRNA vaccines include only a few allergens, especially – polyethylene glycol and related molecules. Polyethylene glycol is not a part of any other registered vaccine. The reason for contraindication is also an immediate allergic reaction on the related molecule of polysorbate which is used in vaccines as a stabilizer. However, allergy to these substances is very rare. Contact dermatitis, food allergies, pollen allergies, or latex allergies are not contraindications to vaccination. Vaccination centers must be equipped to cure possible anaphylactic reactions. Every staff member must be trained to recognize such a reaction and must be able to handle the situation properly. The training of the staff must be documented. The vaccination center must dispose of at least adrenaline, a tonometer, a stethoscope, and possibly other equipment to handle the situation. Written instructions must be also well prepared for this scenario. All vaccinated people with an immediate allergic reaction to any vaccine substance must be monitored in a medical facility at least 30 minutes after vaccination, standard monitoring period is 15 minutes.
People with autoimmune diseases
Currently, due to a lack of research knowledge, we are unable to say much about Covid-19 vaccine safety and effectiveness for individuals with autoimmune diseases despite these individuals have been found eligible to be in the sample for clinical research studies. Individuals with autoimmune diseases who participated in clinical studies and got mRNA vaccine did not statistically differ from the control group (with placebo) in terms of occurrence of symptoms typical for autoimmune diagnosis or inflammatory disorders. Thus, individuals with autoimmune diseases with no other contraindication can be vaccinated.
People with comorbidities
Some chronic diseases are increasing the risk of severe Covid-19 disease and subsequently the risk of death. The safety and efficacy of the vaccine have been proved in the research studies examining the impact on the cohort of people with comorbidities. The risks are comparable with the cohort of people without comorbidities. The list of chronic diseases includes hypertension, diabetes mellitus, asthma, lung, liver, and renal diseases, chronic (stabilized and well-controlled) HIV, HCV, and HBV infection. Vaccination is definitely recommended for individuals with chronic diseases.
People with immunodeficiency
We recommend vaccination for any individual with immunodeficiency including individuals with oncological disease and individuals on immunosuppressive therapy. These individuals have an increased risk of serious Covid-19 disease and consequently increased risk of death. Despite vaccine effectiveness may be lower for these individuals, expected benefits from the vaccination are considered to be higher.
Pregnant women have an increased risk of a more serious course of Covid-19 disease, including death, compared to non-pregnant women of the same age. Other factors that increase the risk of a more serious course of Covid-19 disease in pregnant women are: age over 35 years, obesity, pregestational diabetes mellitus, pre-existing hypertension, and other chronic diseases. Covid-19 may increase the risk of preterm birth and other perinatal complications.
The benefit of vaccination far outweighs the theoretical risk of vaccination, and therefore vaccination of pregnant women is recommended. It is possible to be vaccinated at any stage of pregnancy.
In its report, the Czech Vaccinological Society recommends the use of mRNA vaccines for pregnant women.
Breast-feeding women do not have an increased risk of a more serious course of Covid-19 disease.
There is little data available on the vaccination of breastfeeding women. Due to their mechanism of action in the human body, Covid-19 vaccines are not considered to be dangerous to breastfeeding women and their breastfed children.
Antibodies generated after the vaccine pass into breast milk, which is beneficial for the breastfed baby. The Czech Vaccinological Society, therefore, recommends vaccination of breastfeeding women.
In its report, the Czech Vaccinological Society recommends the use of mRNA vaccines for breastfeeding women.